From U.S. Pat. No. 3,820,089 there is known a magnetoresistive bridge for detection of magnetic bubbles. In the above-noted bridge, all four magnetic films are disposed in a common plane, but no coupling exists between the magnetic films.
From U.S. Pat. No. 3,546,579 there is known a magnetometer including thin films, in which the thin films are magnetized along the direction of the easy magnetic axes. The magnetic films are free from any coupling between each other.
In U.S. Pat. No. 3,649,912, there is described a so-called compensated measurement transducer, in which magnetoresistive semi-conductor diodes are disposed in an air gap of the magnetic core. The circuit for the reduction of the inverse effect of Hall generators is known from U.S. Pat. No. 3,555,310.
From the IEEE action on magnetics, November 1976, pages 813 to 815, there is known a magnetoresistive current detector, including a conductor which carries a current to be measured generating an external field, four bridge elements connected to one another so as to constitute a Wheatstone bridge, and wherein the Wheatstone bridge is adapted to be fed by a supply current from a current- or voltage-source and includes two pairs of ferromagnetic and magnetoresistive thin films having hard and easy axes, respectively, and wherein the external magnetic field has a direction along the direction of the hard magnetic axis of each of the thin films, and the thin films of each pair are magnetostatically coupled to one another, so that the portion of the supply current flowing in each thin film of each pair generates an auxiliary magnetic field having a direction along the hard magnetic axes or the other thin film of the same pair. The thin films of each pair have, however, different respective thickness, so that the resistances of the thin films varying in respective opposite directions do not mutually cancel each other, thus providing a sufficiently large output signal.